Below figure shows a simple ring main, with a single infeed at Bus A and three load busbars which I think is very close to your system conceptually. I transfer this example from ALSTOM PROTECTIVE RELAYS APPLICATION GUIDE in here; you can try to new setting calculation with following this example. Settings for the directional relays R2- R7 and non-directional relays R1/R8 are required. Maximum load current in the ring is 785A (maximum continuous current with one transformer out of service), so 1000/1A CT